Hydraulic antivibration device arrangement, hydraulic antivibration device, and car body side bracket

ABSTRACT

A hydraulic antivibration device arrangement capable of achieving a downsizing and weight reduction, and a reduction of booming noise by suppressing a reaction force to impingement upon stopper action is provided. By disposing a protuberant rubber portion  35  at an upper end of a main body member  2,  its spacing distance from a roll center can be lengthened, the reaction force to impingement can be diminished, and input load to the main body member  2  can be diminished. Consequently, reduction of rigidity and strength required for respective components as well as enhancement of durability is possible, which permits to make the components thin-walled thereby making a hydraulic antivibration device arrangement  100  lightweight as a whole. Diminishing of such reaction force upon stopper action also enables vibrations input through a car body side bracket  120  to the body frame to be suppressed, thereby reducing the generation of booming noise.

TECHNICAL FIELD

This invention relates to a hydraulic antivibration device arrangement,a hydraulic antivibration device and a car body side bracket, and moreparticularly, to such hydraulic antivibration device arrangement,hydraulic antivibration device and car body side bracket that arecapable of achieving a downsizing and weight reduction and a reductionof booming noise by suppressing a reaction force to impingement uponstopper action.

BACKGROUND ART

As an antivibration device for supporting and fixing a vibrationgenerator such as an automotive engine or transmission so as not totransmit vibrations thereof to a vehicle body frame, hydraulic styleantivibration devices are known.

Hydraulic antivibration devices each have a liquid-sealed chambercomparted by partition means into a first and a second liquid chambers,which are put in communication with each other through an orifice, andperform both a vibration attenuating function and a vibration insulatingfunction due to a fluid fluidization effect through the orifice betweenthe first and second liquid chambers and a vibration-deadening effect ofa vibration-isolating base.

Of these, there is such a hydraulic antivibration device that thepartition means comprises an elastic partition membrane made ofrubber-like elastomer material and a pair of displacement-regulatingmembers regulating the displacement amount of the elastic partitionmembrane from both sides thereof.

According to the hydraulic antivibration device of this type, when arelatively small amplitude vibration is input, the elastic partitionmembrane is subjected to reciprocating displacement, thereby absorbing ahydraulic pressure fluctuation between both liquid chambers, so that alow dynamic spring characteristic can be obtained. On the other hand,when a relatively large amplitude vibration is input, for example, owingto irregularities of the travelling road surface, thedisplacement-regulating members serve to regulate the displacementamount of the elastic partition membrane from its both sides to enhancethe membrane stiffness, thereby rendering the fluid easy to fluidizebetween both liquid chambers through the orifice, so that a high dampingcharacteristic can be obtained.

However, a problem with the hydraulic antivibration device of this typewas that because of the construction that the elastic partition membraneis made to impinge (abut) on the displacement-regulating members, thedisplacement-regulating members oscillate upon impinging, whichoscillation is transmitted to the body frame to generate a strange sound(noise).

As a technology of suppressing the generation of such strange sounds,for example, WO 02/095259 A1 discloses, in connection with a hydraulicantivibration device constructed so that a vibration-isolating base madeof rubber-like elastomer material is interconnected between a bossmember and a cylindrical main body member and a liquid-filled chamber isformed between a diaphragm provided at the main body member and avibration-isolating base, a technology for connecting the boss member toa body frame side while connecting the main body member to an engineside (Patent Reference 1).

According to this technology, it is possible to construct a part of avibration transmission path from partition means (the elastic partitionmembrane and the displacement-regulating members) to the vehicle bodyframe by the vibration-isolating base, and consequently, even if theelastic partition membrane impinges on the displacement-regulatingmembers, which in turn oscillate, it is possible to suppresstransmission of the oscillation to the body frame by virtue of thevibration insulating effect of the vibration-isolating base constitutinga part of the vibration transmission path, thus reducing the generationof strange noises.

[Patent Reference 1] WO 02/095259A1 (FIGS. 1, 2, etc.)

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

In the above-mentioned hydraulic antivibration device as shown in FIG. 1of Patent Reference 1, the car body side bracket is configured in aframe form and its internal face is configured as a stopper surface.That is, at the external face of the main body member, a rubber stoppermember is provided to abut on the internal face of the car body sidebracket so that an excessive displacement of the hydraulic antivibrationdevice can be regulated.

However, the aforesaid hydraulic antivibration device was constructed sothat the rubber stopper member is formed in such a longitudinallyelongated shape extending along the height direction of the main bodymember that for example, against the displacement in a roll motiondirection, the overall rubber stopper member is brought into planeabutment on the internal face of the car body side bracket at one time.Therefore the problem here was that upon stopper action to the rollmotion direction, a reaction force to impingement is so large that inputloads to the main body member and the car body side bracket becomelarge.

As a result, there were further problems that the necessity of makingthe respective elements thick-walled to ensure their rigidity andstrength is created, causing a weight increase and the oscillationascribed to the impingement is transmitted to the body frame to generatebooming noise. Further, in order to ensure the stroke amount in the rollmotion direction, it is necessary to enlarge the distance betweenopposed internal faces of the car body side bracket, which fact furtherran into the problem that the device as a whole is made large-sized.

In view of the problems described above, this invention has been made,and it is an object of the present invention is to provide a hydraulicantivibration device arrangement, a hydraulic antivibration device and acar body side bracket that are capable of achieving a miniaturizationand weight reduction of respective constituent elements and a reductionof booming noise by suppressing input load upon stopper action.

Solution Means of the Problems

In order to attain this object, the hydraulic antivibration devicearrangement as set forth in claim 1 comprises:

-   -   a hydraulic antivibration device which comprises a cylindrical        main body member, a boss member positioned on a lower end face        side of the main body member, a vibration-isolating base made of        rubber-like elastomer material connecting the boss member and        the main body member, a diaphragm attached to the main body        member to define a liquid-filled chamber between the diaphragm        and the vibration-isolating base, partition means comparting the        liquid-filled chamber into a first liquid chamber on the        vibration-isolating base side and a second liquid chamber on the        diaphragm side, an orifice putting the first liquid chamber and        the second liquid chamber into communication with each other,        and a rubber stopper member made of rubber-like elastomer        material provided on an outer surface of the main body member;    -   an engine side bracket formed integrally with the main body        member of the hydraulic antivibration device and to be coupled        to the engine side; and    -   a car body side bracket that includes a bottom face part to        which the boss member of the hydraulic antivibration device is        locked and fixed, a pair of sidewall parts provided        perpendicularly from the bottom face part and opposed to each        other, interposing the hydraulic antivibration device        therebetween, and a top face part interconnecting the pair of        the sidewall parts and opposed to the bottom face part,        interposing the hydraulic antivibration device between the        bottom face part and the top face part, and is adapted to be        connected to a body frame side;        and is constructed to support the engine in a suspending manner        and to be capable of bringing the rubber stopper member provided        on the outer surface of the main body member into abutment on        internal faces of the sidewall parts of the car body side        bracket, thereby regulating displacement of the engine in a roll        motion direction at least upon acceleration, which arrangement        is characterized in that the rubber stopper member is provided        with a protuberant rubber portion protruding from the outer        surface of the main body member toward the sidewall parts of the        car body side bracket and tapering in cross-section, and the        protuberant rubber portion is situated at least on the upper end        side above a vertically intermediate position of the main body        member and configured in a transversely elongated body extending        straight widthwise toward the sidewall parts of the car body        side bracket while facing the sidewall parts in a spaced        relation of a definite distance; and that the sidewall parts of        the car body side bracket each includes an abutment sidewall        portion having an abutment face on which the protuberant rubber        portion of the rubber stopper member abuts and a thick-walled        sidewall portion formed to be more thick-walled than the        abutment sidewall portion, and the abutment face of the abutment        sidewall portion is formed to be depressed from the inner face        of the thick-walled sidewall portion toward receding from the        outer surface of the main body member.

The hydraulic antivibration device arrangement as claimed in claim 2relates to the hydraulic antivibration device arrangement of claim 1,and is characterized in that the main body member is provided with aprojecting main body portion projecting from the outer surface of themain body member toward the sidewall parts of the car body side bracket,and the projecting main body portion is situated on the upper end sideabove the vertically intermediate position of the main body member, andconfigured in the transversely elongated body extending straightwidthwise toward the sidewall parts while facing the sidewall parts ofthe car body side bracket to be spaced apart a definite distance andencased in the protuberant rubber portion of the rubber stopper member.

The hydraulic antivibration device arrangement as claimed in claim 3relates to the hydraulic antivibration device arrangement recited inclaim 1 or 2, and is characterized in that the main body member isprovided with a cutout portion (undercut) defined by cutting a part ofan underside thereof situated on the opposite side to the engine sidebracket and on the boss member side.

The hydraulic antivibration device arrangement as claimed in claim 4 isconcerned with the hydraulic antivibration device arrangement recited inany one of claims 1 to 3, and characterized in that the main body memberis provided with a thin-walled portion formed by depressing the outersurface thereof opposite to the engine side bracket.

The hydraulic antivibration device arrangement as claimed in claim 5 isconcerned with the hydraulic antivibration device arrangement recited inany one of claims 1 to 4, and characterized in that there are provided aprotruding pin projecting from one of the bottom face part of the carbody side bracket and the boss member and a slit portion serving as aguide path for the protruding pin and extending at the other of thebottom face part of the car body side bracket and the boss member, andthe slit portion has an abutment portion provided at its extendingextremity, and that the bottom face part of the car body side brackethas a through-hole for a bolt and the boss member has a locking hole forthe bolt so that when the protruding pin is made to abut on the abutmentportion of the slit portion, the through-hole and the locking hole forthe bolt may be put in communication with each other.

The hydraulic antivibration device arrangement as claimed in claim 6 isconcerned with the hydraulic antivibration device arrangement recited inclaim 5, and characterized in that two pieces of the protruding pins areprovided projectingly at one of the bottom face part of the car bodyside bracket and the boss member, and two pieces of the slit portionsare provided to extend at the other of the bottom face part of the carbody side bracket and the boss member, and that the two protruding pinsand the two slit portions are constructed so that when the twoprotruding pins are made to abut on the abutment portions of the twoslit portions respectively, the through-hole and the locking hole forthe bolt may be put into communication with each other.

The hydraulic antivibration device arrangement as claimed in claim 7 isconcerned with the hydraulic antivibration device arrangement recited inany one of claims 1 to 6, and characterized in that the rubber stoppermember includes a rebound side rubber portion and a bound side rubberportion provided respectively on an upper end surface and a lower endsurface of the main body member, and the rebound side rubber portion andthe bound side rubber portion are constructed so as to be capable ofregulating the displacement in a rebound direction and a bound directionof the hydraulic antivibration device by abutment of them on the topface part and the bottom face part of the car body side bracket,respectively.

The hydraulic antivibration device arrangement as claimed in claim 8relates to the hydraulic antivibration device arrangement recited inclaim 7, and is characterized in that the projecting main body portionof the main body member projecting from the outer surface thereof issituated on an uppermost end side of the main body member andconstructed so that upper end surfaces of the projecting main bodyportion and the main body member are flush with each other.

The hydraulic antivibration device as claimed in claim 9 is used for thehydraulic antivibration device arrangement as claimed in any one ofclaims 1 to 8.

The car body side bracket as claimed in claim 10 is used for thehydraulic antivibration device arrangement as claimed in any one ofclaims 1 to 8.

EFFECTS OF THE INVENTION

According to the hydraulic antivibration device arrangement of claim 1,because the protuberant rubber portion is provided above the verticallyintermediate position of the main body member, when the protuberantrubber portion is made to abut on the sidewall parts of the car bodyside bracket, thereby regulating the displacement of the hydraulicantivibration device, the effect accrues that it is possible to make theinput loads to the main body member and to the car body side bracketsmall.

More specifically, where the engine is displaced in the roll motiondirection, at the hydraulic antivibration device, the upper end side ofthe main body member is oscillated like a pendulum relative to the bossmember as a fixed point toward the sidewall parts of the car body sidebracket. At that time, because of the feature that the protuberantrubber portion of the main body member is situated on the upper end sidehigher than the vertically intermediate position of the main bodymember, the distance in which the protuberant rubber portion is spacedapart from the roll center of the engine can be made longer by thatamount. If so, inasmuch as a roll moment is determined by the product ofa distance and a force, it is possible to make a reaction force toimpingement of the protuberant rubber portion smaller and consequently,it is possible to make input loads to the main body member and the carbody side bracket small by that amount.

As a result of that, it is possible not only to enhance the durability,but also to lower stiffness and strength required for respectiveconstituent elements, and consequently, the effect accrues that it ispossible to make them thin-walled by that amount, thus making theoverall arrangement lightweight. Further if the reaction force toimpingement upon action of the rubber stopper member can be diminishedas mentioned above, it is possible to suppress the vibrations inputthrough the car body side bracket to the body frame and hence, theeffect accrues that it is possible to reduce the generation of boomingnoise by that amount.

Further because of such configuration of the protuberant rubber portionthat assumes a transversely elongated shape extending straight in thewidth direction of the sidewall parts of the car body side bracket whilefacing the sidewall parts in a spaced relation of a definite distance,the effect accrues that it is possible to secure simultaneously itspressure-receiving area and the distance spacing apart from the rollmotion center.

As a consequence, due to enlargement of the pressure-receiving area, adispersion effect of the input load can be obtained, so that it ispossible to enhance the durability. On the other hand, due to thesecurement of the spacing distance, it is possible to make the inputloads to the main body member and to the car body side small therebyachieving a weight reduction and a reduction of booming noisesimultaneously.

The car body side bracket includes the sidewall parts each of whichconsists of an abutment sidewall portion having an abutment face, onwhich the protuberant rubber portion of the rubber stopper member abuts,and a thick-walled sidewall portion formed to be more thick-walled thanthe abutment sidewall portion, wherein the abutment face of the abutmentsidewall portion is depressed from the inner face of the thick-walledsidewall portion toward receding from the outer surface of the main bodymember.

Thus due to the depressed formation, it becomes possible to make theabutment face of the abutment sidewall portion to be spaced apart fromthe protuberant rubber portion of the rubber stopper member. Thereforethe effect accrues that it is possible to secure the stroke amount inthe roll motion direction without the necessity of making the car bodyside bracket itself large-sized as is the case with existing products.Further effect obtainable is that due to the depressed amount of thesidewall portions, it is possible to enhance the durability of theoverall car body side bracket by the constitution of the thick-walledsidewall portions, while attaining a weight reduction of the overall carbody side bracket.

Here, such depressed provision of the abutment faces like this (namely,making the abutment sidewall portions thin-walled) is usuallyimpossible, inasmuch as such abutment face is subject to input load fromthe protuberant rubber portion, but has become possible for the firsttime in this invention by constructing the car body side bracket in theform of a frame consisting of the bottom face part, the sidewall partsand the top face part and further providing the thick-walled sidewallportion thicker than the abutment sidewall portion to dispose it at thelocation where the abutment sidewall portion is interposed between thethick-walled sidewall portion and the top face part, whereby weightreduction and securement of the strength can be simultaneously achieved.

According to the hydraulic antivibration device arrangement as claimedin claim 2, an additional effect to the effects achieved by thehydraulic antivibration device arrangement as claimed in claim 1 isachieved in that because the main body projecting portion is provided inthe position where it is encased in the protuberant rubber portion,namely, on the upper end side above the vertically intermediate positionof the main body member, it is possible to elevate the rigidity andstrength of the main body member while suppressing an weight increase ofthe main body member, thereby enhancing its durability.

That is, according to the invention, because the protuberant rubberportion (the position where a load is input) is made eccentric on theupper end side of the main body member, it is unnecessary to reinforcethe vertical entirety of the main body member as is the case withconventional products, but it suffices to reinforce only the upper endside by the projecting main body portion, or in other words it ispossible to make the lower end side of the main body member morethin-walled, and hence it is possible to attain a weight reduction ofthe hydraulic antivibration device arrangement as a whole, by thatamount.

In addition, because the projecting main body portion is configured in atransversely elongated body extending straight in the width direction ofthe sidewall parts of the car body side bracket while facing thesidewall parts at a definite distance, the effect accrues that it ispossible simultaneously to ensure the pressure-receiving area and toensure the spacing distance from the roll motion center.

As a consequence, due to the extended pressure-receiving area, it ispossible to obtain an input load dispersion effect and hence, thedurability can be enhanced, while due to the securement of the spacingdistance of the projecting main body portion formed in a transverselyelongated shape from the roll motion center, it is possible to make theinput loads to the main body member and the car body side bracket smallas described above, so that a weight reduction and a reduction ofbooming noise can be achieved simultaneously.

According to the hydraulic antivibration device arrangement of claim 3,in addition to the effects achieved by the one as recited in claim 1 orclaim 2, further effect is achieved in that because the main body memberhas the cutout portion formed by cutting out a part of the main bodymember, it is possible to make the main body member more lightweight,thereby achieving a weight reduction by that amount of the hydraulicantivibration device arrangement as a whole.

In this invention, because of the constitution that the main body membersupports the engine in a cantilever manner relative to the boss memberas a fixed point, if the top end side of the main body member (namely,opposite side to the engine connecting side) becomes heavier, aresonance point of the main body member thereto will shift to a lowfrequency range (e.g., 500˜600 Hz and its vicinity), which leads to theproblem that a so-called high speed booming noise is generated. Contraryto this, here, the position of the cutout portion is situated on theopposite side to the engine (engine side bracket) while interposing theboss member and consequently, it is possible to render the top end sideof the main body member lightweight. As a result, the effect accruesthat it is possible to shift efficiently the resonance point of the mainbody member toward a high frequency range to suppress securely anyadverse effect upon dynamic characteristics of the hydraulicantivibration device arrangement.

Further in this invention, the main body member is provided, on theupper end side, with a groove or slot, whose sidewall portion is benttoward the inner periphery of the main body member so that it can caulkand fix the diaphragm and others. Here, since the cutout portion issituated on the lower end side of the main body member, there is theeffect that it is possible to avoid a reduction of the space for theformation of the groove by the cutout portion. As a result, it ispossible to fix firmly the diaphragm and so forth.

As described above, the position of the cutout portion is situated onthe top end side of the main body member and thus not a location whereit abuts on the bottom face part of the car body side bracket. Thereforethe effect accrues that even where the main body member is provided onits lower end side with the bound side rubber portion so as to becapable of exhibiting a stopper action of the bound side, it is possibleto achieve a weight reduction while suppressing the reduction ofdurability of the main body member due to the formation of the cutoutportion to the minimum limit.

According to the hydraulic antivibration device arrangement of claim 4,in addition to the effects achieved by the one as recited in any one ofclaims 1 to 3, the effect accrues that because the main body member isprovided with a thin-walled portion formed by depressing a part of theouter surface thereof, it is possible to make the main body member morelightweight, achieving a weight reduction of the hydraulic antivibrationdevice arrangement as a whole by that amount.

Here, since the position of the thin-walled portion is situated on theopposite side to the engine (engine side bracket) while interposing theboss member, it is possible to make the top end side of the main bodymember lightweight. As a result, further effect accrues that it ispossible to shift efficiently the resonance point of the main bodymember toward high frequency range as stated above, thereby suppressingreliably any adverse effect upon dynamic characteristics of thehydraulic antivibration device.

Again in this invention, the rubber membrane is formed on the innerperiphery side of the main body member, and the partition means and thediaphragm are inserted while faying with the rubber membrane. At thattime, since the position of the thin-walled portion is situated on theouter surface of the main body member, due to the fact that thethin-walled portion is partly formed, the effect is yielded that it ispossible to avoid that the membrane thickness of the rubber membranebecomes uneven in the circumferential direction. As a consequence, it ispossible to fay evenly full outer peripheries of the partition means andthe diaphragm with the rubber membrane, so that it is possible toprevent leak of liquid to suppress a reduction of the dynamiccharacteristics.

According to the hydraulic antivibration device arrangement of claim 5,in addition to the effects achieved by the one as recited in any one ofclaims 1 through 4, the following effects are achieved: the protrudingpin is provided projectingly from one of the bottom face part of the carbody side bracket and the boss member, and in order to form a guide pathfor the protruding pin, the slit portion is provided on the other of thebottom face part of the car body side bracket and the boss member.

Because of that, even though a distance between opposed faces of thebottom face part and the top face part of the car body side bracketconfigured in the form of a frame is narrower than the height dimensionof the hydraulic antivibration device, it is possible to receive theprotruding pin in the slit portion, thereby extending the distancebetween the opposed faces in comparison with the height dimension. As aresult, when inserting the hydraulic antivibration device into the frameof the car body side bracket, its inserting operation can be readilyconducted, whereby the working efficiently can be enhanced. It is alsopossible to construct the distance between the opposed faces narrower,which yields the effect that by that amount, it is possible to downsizethe overall hydraulic antivibration device arrangement.

In the operation of inserting the hydraulic antivibration device intothe frame of the car body side bracket, because the slit portion servesas a guide path for the protruding pin, the effect accrues that theinsertion operation efficiency can be enhanced. In addition, thethrough-hole for bolt at the bottom face part and the bolt locking holeof the boss member can be readily put into communication with each otherby moving the protruding pin up to the terminal end of the guide path tomake it to abut on the abutment face. Therefore the effect accrues thatit is possible to lock so readily the bolt to the bolt locking hole thatthe locking operation efficiency can be enhanced.

Further the slit portion suffices to have an equal level of width tothat of the protruding pin, and consequently, it is possible to suppressthe machining amount to the bottom face part of the car body sidebracket to the minimum limit and its machining operation is also easy.That is, since there is no need to conduct a complex machining to thebottom face part of the car body side bracket in an extensive area as inconventional products, the effect accrues that it is possible tosuppress an increase in machining cost and a reduction in strength dueto the provision of the slit portions.

According to the hydraulic antivibration device arrangement of claim 6,in addition to the effects achieved by the one as recited in claim 5,there exists the effect that because the protruding pin and the slitportion are formed in respective two pieces and constructed so that wheneach of the protruding pins is brought into abutment on the abutmentportion of each of the slit portions, the bolt through-hole and the boltlocking hole may be put into communication with each other, it ispossible to conduct positioning, without rotation, of the hydraulicantivibration device (the boss member) to the car body side bracket (thebottom face part). As a consequence, in locking operation of bothmembers, as a further effect, it is possible to put the boltthrough-hole and the bolt locking hole into communication with eachother easily and securely, and hence, the working efficiency of thelocking operation can be enhanced vastly.

According to the hydraulic antivibration device arrangement of claim 7,in addition to the effects achieved by the one as recited in any one ofclaims 1 through 6, the effect accrues that because the rubber stoppermember includes the rebound side rubber portion and the bound siderubber portion on the upper end face and the lower end face of the mainbody member, respectively, it is possible to regulate securelydisplacements to the rebound direction and the bound direction.

That is, with conventional products, because the rebound side and thebound side rubber portions were provided on the outer surface of themain body member, there were problems that upon inputting of a largedisplacement, these rubber portions deform excessively, causing crackingor failure and that the main body member impinges on the top face partand the bottom face part of the car body side bracket, generating astrange noise, but this invention permits to solve these problems by theprovision of them on the upper and lower end faces of the main bodymember.

According to the hydraulic antivibration device arrangement of claim 8,in addition to the effects achieved by the one as recited in claim 7,the effect accrues: the projecting main body portion providedprojectingly from the outer surface of the main body member is situatedon the uppermost end side of the main body member, and the upper endfaces of the projecting main body portion and the main body member areconstructed to be flush with each other; therefore even in the casewhere the groove for caulking and fixing is defined on the upper endsurface of the main body member, a space for disposing the rebound siderubber portion can be sufficiently ensured. That is, it is possible toachieve a reinforcing effect to the stopper action by the protuberantrubber portion to the roll direction and simultaneously the securementof the disposition space mentioned above and a reinforcing effect to thestopper action to the rebound direction.

According to the hydraulic antivibration device of claim 9, it ispossible to achieve similar effects to those of the hydraulicantivibration device used for the hydraulic antivibration devicearrangement as recited in any one of claims 1 through 8.

According to the car body side bracket of claim 10, it is possible toachieve similar effects to those of the car body side bracket used forthe hydraulic antivibration device arrangement as recited in any one ofclaims 1 through 8.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a top plan view of a hydraulic antivibration devicearrangement in a first embodiment of the invention, and (b) is a sideelevation of the hydraulic antivibration device arrangement when viewedfrom the direction of an arrow mark Ib in FIG. 1(a).

FIG. 2 is a sectional view of the hydraulic antivibration devicearrangement taken along II-II line in FIG. 1(a).

FIG. 3(a) is a top plan view of a car body side bracket, (b) is a frontelevation of the car body side bracket, and (c) is a bottom plan view ofthe car body side bracket.

FIG. 4 is a top plan view of a main body member.

FIG. 5(a) is a front elevational view of the main body member whenviewed from the direction of an arrow mark Va in FIG. 4, and (b) is aside elevational view of the main body member when viewed from thedirection of an arrow mark Vb in FIG. 4.

FIG. 6(a) is a sectional view of the main body member taken alongVIa-VIa line in FIG. 4, and (b) sectional view of the main body membertaken along VIb-VIb line in FIG. 4.

FIG. 7 is a cross-sectional view of the hydraulic antivibration devicearrangement in a second embodiment.

FIG. 8(a) is a perspective view of a boss member, and (b) is aperspective view of a bottom face part.

DESCRIPTION OF REFERENCE CHARACTERS

100, 200 hydraulic antivibration device arrangement 110, 210 hydraulicantivibration device 1 boss member 11 bolt locking hole 12, 212protruding pin 2 main body member 2a projecting main body portion 2dcutout portion 2e thin-walled portion 3 vibration-isolating base 33rubber stopper member 34 rebound side rubber portion 35 protuberantrubber portion 36 bound side rubber portion 5 diaphragm 6 liquid-filledchamber 6A first liquid chamber 6B second liquid chamber 7 partitionmeans 71 orifice 120, 220 car body side bracket 122 bottom face part122a through-hole for bolt 122b, 222b slit portion 122b1, 222b1 abutmentportion 123 sidewall part 123a abutment sidewall portion 123a1 abutmentface 123b thick-walled sidewall portion 124 top face part 130 engineside bracket EG engine BF body frame a roll direction on theacceleration side ◯ central axis

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the invention will be hereinafter describedwith reference to the accompanying drawings. FIG. 1(a) is a top planview of the hydraulic antivibration device arrangement 100 in a firstembodiment, and FIG. 1(b) is a side elevation of the hydraulicantivibration device arrangement 100 when viewed from the arrow markdirection Ib in FIG. 1(a).

The hydraulic antivibration device arrangement 100 is a hydraulic stylevibration isolator for supporting the engine EG for automobiles in acantilever suspended manner so as to prevent vibrations of the engine EGfrom being transmitted to the body frame BF. As shown in FIG. 1, it ismainly made up of the hydraulic antivibration device 110, the car bodyside bracket 120 connecting the hydraulic antivibration device 110 tothe body frame BF side, and the engine side bracket 130 connecting thehydraulic antivibration device 110 to the engine EG side.

The car body side bracket 120 is adapted to be locked and fixed throughthree bolts (not shown) each inserted into an attachment hole 121 to thebody frame BF while the engine side bracket 130 adapted to be locked andfixed through three bolts (not shown) each inserted through anattachment hole 131 to a coupling member EG1 (to the engine EG).

At the hydraulic antivibration device 110, the boss member 1 is lockedand fixed to the car body side bracket 120 and the main body member 2 isformed integrally with the engine side bracket 130 (cf. FIG. 2).Consequently, a shared load of the engine EG oriented toward thedownward direction of FIG. 1(b) acts on the hydraulic antivibrationdevice 110.

FIG. 2 is a cross-sectional view of the hydraulic antivibration devicearrangement 100 taken along II-II line of FIG. 1(a). In FIG. 2, thecenter line indicated in a one dot-dash line indicates the center axis Oof the hydraulic antivibration device 110. FIG. 2 shows a sidewallportion of a groove 2 c prior to being subjected to bending working.

As shown in FIG. 2, the hydraulic antivibration device 110 is comprisedmainly of the boss member 1 to be attached through the car body sidebracket 120 to the body frame BF (cf. FIG. 1(b)), the main body member 2in a cylindrical shape formed integrally with the engine side bracket130 and to be attached through the engine side bracket 130 to the engineEG side (cf. FIG. 1(b)), and the vibration-isolating base 3interconnecting both members 1, 2 and made of a rubber-like elastomermaterial.

The boss member 1 is, as shown in FIG. 2, configured from aluminum alloyor the like in the shape of a generally frustum of a cone incross-section upwardly converging and symmetric about the central axis Oand provided on its lower end face with the bolt locking hole 11 forlocking to the car body side bracket 120 which is recessed upwardly. Onboth sides of the bolt locking hole 11, two protruding pins 12 fitted inthe car body side bracket 120 (the slit portions 122 b on the bottomface part 122 as described below) are provided to project towarddownwardly (the lower side in FIG. 2).

The main body member 2 is configured in a cylinder shape having openupper and lower ends (the upper side and lower side in FIG. 2) fromaluminum alloy, etc. The main body member 2 is formed on its outersurface (the deep side from the paper face of FIG. 2) integrally withthe engine side bracket 130.

Again the main body member 2 includes the projecting main body portion 2a in a generally rectangular shape in cross-section that is providedprojectingly from the outer surface toward the sidewall parts 123 of thecar body side bracket 120, and a receptive surface portion 2 b in agenerally triangular shape in cross-section that is providedprojectingly from the inner peripheral surface toward the central axis Oside.

The projecting main body portion 2 a is situated at the vertically upperend of the main body member 2 (the up-and-down direction in FIG. 2) andencased in the protuberant rubber portion 33, which will be laterdescribed. The receptive surface portion 2b is situated slightlydownwards of the vertically intermediate position of the main bodymember 2, wherein its upside serves as a receiving face for thepartition means 7 as described below while its downside serves as areceiving face for the vibration-isolating base 3.

The projecting main body portion 2 a is formed in a transverselyelongated body extending straight in the width direction (theperpendicular direction to the paper face in FIG. 2) of the sidewallparts 123 while facing the sidewall parts 123 of the car body sidebracket 120 at a definite distance (cf. FIGS. 4 or 5).

As illustrated in FIG. 2, the vibration-isolating base 3 is formed froma rubber-like elastomer material in the shape of a generally frustum ofcone in cross-section symmetric about the central axis O and downwardlyconverging, and vulcanization bonded between a slanting face of the bossmember 1 and a slanting face (the underside) of the receptive surfaceportion 2 b of the main body member 2. The underside of the receptivesurface portion 2 b is made parallel to the slanting face of the bossmember 1 and hence, it is possible to prevent a deformation due topermanent set in fatigue of the vibration-isolating base 3 in comparisonwith the case where the vibration-isolating base 3 is vulcanizationbonded to the inner peripheral surface parallel to the central axis O ofthe main body member 2.

According to the hydraulic antivibration device 110 in the firstembodiment, because of the constitution that the boss member 1 iscoupled to the body frame BF side and the main body member 2 is coupledto the engine EG (vibration generator) side, a part of the vibrationtransmitting path from the partition means 7 to the body frame BF isconstructed by the vibration-isolating base 3.

As a consequence, for instance, even if an elastic partition membrane 8of the partition means 7 impinges on an upper or a lower sandwichingmember 9, 10 to oscillate the upper or the lower sandwiching member 9,10, transmission of the oscillation to the body frame BF can besuppressed reliably by the vibration insulating effect of thevibration-isolating base 3 thus reducing largely the generation of astrange sound.

A first and a second rubber membranes 31, 32 covering the innerperipheral face of the main body member 2 are joined to thevibration-isolating base 3, as shown in FIG. 2. The first rubbermembrane 31 are fayed with peripheral marginal portions of upper andlower sandwiching members 9, 10 and the diaphragm 5, which will be laterdecribed.

Here, on the outer surface of the main body member 2, there is providedthe stopper rubber part 33 made of rubber-like elastomer, which is inturn joined through the second rubber portion 32 to thevibration-isolating base 3.

The stopper rubber part 33 serves to abut on the inner face of the carbody side bracket 120 (the bottom face part 122, the sidewall parts 123,and the top face part 124) thereby regulating displacement of the engineEG (cf. FIG. 1) thus acting as a stopper member. The stopper rubber part33 is mainly made up of the rebound side rubber portion 34, theprotuberant rubber portion 35, the bound side rubber portion 36, and atransitional rubber portion 37 linking the latter two, all of which areintegrally formed.

The rebound side rubber portion 34 and the bound side rubber portion 35are provided on the upper end face and the lower end face (the upperside face and the lower side face in FIG. 2) of the main body member 2,respectively, which abut on internal faces of the top face part 124 orthe bottom face part 122 of the car body side bracket 120 thereby toregulate the displacement of the hydraulic antivibration device 110 (theengine EG) in the rebound direction (the upward direction in FIG. 2) orthe bound direction (the downward direction in FIG. 2).

On the other hand, the protuberant rubber portion 35 is providedprojectingly to be directed from the outer surface of the main bodymember 2 toward the sidewall parts 123 of the car body side bracket 120,and serves to abut on the sidewall parts 123 thereby to regulate thedisplacement of the hydraulic antivibration device 110 (the engine EG)in the roll direction (the arrow mark direction a or the arrow markdirection d in FIG. 2).

Upon abrupt acceleration or deceleration (e.g., upon first speed fullgear acceleration) or accidental loading, the transitional rubberportion 37 abuts on the sidewall parts 123 (thick-walled sidewallportions 123 b), whereby displacements in the fore and aft direction(the lateral direction in FIG. 2) are regulated.

Here, displacements of the engine EG in the lateral direction(perpendicular direction to the paper face of FIG. 2) are regulated byanother vibration isolator supporting the engine EG and consequently, inthe hydraulic antivibration device arrangement 100 of this invention itis possible to dispense with any stopper mechanism for regulatingdisplacements in the lateral direction.

The protuberant rubber portion 35 is configured, as illustrated in FIG.2, in a tapered shape in cross-section narrowing gradually in widthtoward the car body side bracket 120. Because of that configuration, itis possible to bring it into moderate impingement on the sidewall parts123, and hence it is possible to suppress the generation of boomingnoise and to suppress a reaction force to impingement thereby to enhancethe durability.

Moreover, the protuberant rubber portion 35 is disposed at a locationwhere it encases the projecting main body portion 2 a of the main bodymember 2, and configured, similarly to the projecting main body portion2 a, in a transversely elongated body which extends straight in thewidth direction (the perpendicular direction to the paper face of FIG.2) of the sidewall parts 123 while facing the sidewall parts 123 of thecar body side bracket 120 at a definite distance.

The arrow mark direction a shown in FIG. 2 indicates the roll directionupon acceleration while the arrow mark direction d indicates the rolldirection upon deceleration. The roll center of the engine EG (cf.FIG. 1) is situated in a lower position (not shown) in FIG. 2. Where theengine EG is displaced in the roll direction, the hydraulicantivibration device 110 is oscillated, at the upper end side of themain body member 2 thereof, like a pendulum relative to the boss member1 as a stationary point toward the sidewall parts 123 of the car bodyside bracket 120, namely in the arrow mark direction a or d.

In this invention, the protuberant rubber portion 35 is situated on theupper end side of the main body member 2 (the upper side in FIG. 2) asstated above, and hence it is possible to make the spacing distance fromthe roll center of the engine EG to the protuberant rubber portion 35longer by that dimension. The fact that such spacing distance can belengthened permits to diminish the reaction force to impingement,inasmuch as the roll moment is determined by the product of a distanceand a force, and hence it is possible to make input loads to the mainbody member 2 and the car body side bracket 20 smaller, by that amount.

As a result, it is possible not only to enhance the durability, but alsoto lower the stiffness and strength required for the members 2, 120, sothat it is possible to make these members 2, 120 thin-walled by thatdecrement, thereby reducing the weight of the hydraulic antivibrationdevice arrangement 100 as a whole.

Further when the reaction force to impingement upon stopper action canbe made small as stated above, vibrations input through the car bodyside bracket 120 to the body frame BF can be suppressed, so that it ispossible to reduce the generation of booming noise, by that decrement.

Moreover by making thus the protuberant rubber portion 35 (namely, inputposition of a load) eccentric on the upper end side of the main bodymember 2, it is no longer necessary to reinforce the vertical entiretyof the main body member 2 as in the conventional products, but itsuffices to reinforce the upper end side only by the projecting mainbody portion 2 a. Stated another way, it is possible to make the lowerend side of the main body member 2 more thin-walled, so that it ispossible to make the overall hydraulic antivibration device arrangement100 further more lightweight by that amount.

Here, in view of the fact that the input load when regulatingdisplacement in the roll direction is larger on the acceleration sidethan the deceleration side, the vertical dimensions of the protuberantrubber portion 35 and the projecting main body portion 2 a are madelarger on the side regulating the roll direction displacements uponacceleration (the left hand in FIG. 2) than the side regulating the rolldirection displacements upon deceleration (the right hand in FIG. 2).Thereby enhancement of durability and weight reduction can besimultaneously achieved. These projecting dimensions (the lateraldimension in FIG. 2) are made approximately equal to each other on theacceleration side and the deceleration side.

The diaphragm 5 is configured in the form of a rubber membrane having apartial sphere from a rubber-like elastomer material and attached to theupper end part (the upper side in FIG. 2) of the main body member 2. Asa result, the liquid-filled chamber 6 is formed between the lower faceside of the diaphragm 5 and the upper face side of thevibration-isolating base 3.

The liquid-filled chamber 6 is sealed with a non-freezing liquid (notshown) such as ethylene glycol. The liquid-filled chamber 6 is, as shownin FIG. 2, comparted by the partition means 7 (the elastic partitionmembrane 8 and the upper and lower sandwiching members 9, 10) into thefirst liquid chamber 6A on the vibration-isolating base 3 side (thelower side in FIG. 2) and the second liquid chamber 6B on the diaphragm5 side (the upper side in FIG. 2).

The diaphragm 5 is vulcanization bonded to an attachment fitting 51press formed in an annular shape as viewed from the top plane, andattached, as shown in FIG. 2, through the intermediary of the attachmentfitting 51 to the upper end part (the upper part in FIG. 2) of the mainbody member 2.

The partition means 7 is, as described above, to compart theliquid-filled chamber 6 into the first liquid chamber 6A and the secondliquid chamber 6B, and mainly made up of the elastic partition membrane8 configured in a generally disc shape from a rubber-like elastomermaterial, and the upper and the lower sandwiching members 9, 10 pinchingand holding the elastic partition membrane 8 in place in its centralaxis direction.

As shown in FIG. 2, the partition means 7 (the upper and lowersandwiching members 9, 10) is formed, on its outer periphery side, withthe orifice 71 in a generally rectangular shape in cross-section betweenthe inner periphery side (the rubber membrane 31) of the main bodymember 2 and the outer periphery side. The orifice 71 is a constrictivechannel for putting the first liquid chamber 6A and the second liquidchamber 6B into communication with each other.

The orifice 71 is put in communication with the second liquid chamber 6Bthrough a cutout (not shown) defined in the upper sandwiching member 9,and with the first liquid chamber 6A through a cutout formed in thelower sandwiching member 10.

The upper and the lower sandwiching members 9, 10 are pierced with aplurality of openings so that hydraulic pressure fluctuation of theliquid-filled chamber 6 (between the first and the second liquidchambers 6A, 6B) can be transmitted to the elastic partition membrane 8.Thus where a relatively small amplitude vibration is input, the elasticpartition membrane 8 displaces by reciprocating to absorb the hydraulicpressure fluctuation between both liquid chambers 6A, 6B, whereby a lowdynamic spring characteristic can be obtained.

On the other hand, where a relatively large amplitude vibration isinput, for example, owing to the rugged road surface, the upper and thelower sandwiching members 9, 10 regulate the displacement amount of theelastic partition membrane 8 from both sides thereof to elevate themembrane stiffness thereby facilitating the fluidization of fluidthrough the orifice 71 between both liquid chambers 6A, 6B, whereby ahigh damping characteristic can be obtained.

Here, the assembling operation of the hydraulic antivibration device 110is conducted by first fitting the partition means 7 and the diaphragm 5in this order in the main body member 2 from the opening at the upperend side thereof, and then bending working the one sidewall portion(inner periphery side of the main body member 2) of the groove 2 c,which is recessed fully circumferentially at the upper end face of themain body member 2, toward the central axis O side.

As a result, the partition means 7 (the upper and the lower sandwichingmembers 9, 10) is pinched and fixed between the upside of the receptivesurface portion 2 b and the diaphragm 5 in the central axis direction(the vertical direction in FIG. 2) of the hydraulic antivibration device110.

The car body side bracket 120 is a member coupling the hydraulicantivibration device 110 to the body frame BF and serving to receive therubber stopper member 33 upon stopper action thereof, as stated above,and is configured in the form of a frame consisting of the bottom facepart 122, the pair of the sidewall parts 123, and the top face part 124,as shown in FIG. 2.

The bottom face part 122, to which the boss member 1 of the hydraulicantivibration device 110 is locked and fixed, is provided with thethrough-hole for bolt 122 a and the slit portions 122 b. The boltthrough-hole 122 a is constructed to be capable of communicating withthe bolt locking hole 11 of the boss member 1, whereas the slit portion122 b is constructed to be capable of communicating with the protrudingpin 12 of the boss member 1.

The pair of the sidewall parts 123 are provided vertically from thebottom face part 122, so as to face to each other in a spaced relationof a predetermined distance. Between opposed faces of the pair ofsidewall parts 123 there is disposed the hydraulic antivibration device110. The top face part 124 interconnects upper end portions (the upperside in FIG. 2) of the pair of sidewall parts 123 and is opposed to thebottom face part 122.

Each of the sidewall parts 123 consists of an abutment sidewall portion123 a located on the top face part 124 side and a thick-walled sidewallportion 123 b that is located on the bottom face part 122 side andformed in its thickness dimension (the lateral dimension in FIG. 2) tobe more thick-walled than the abutment sidewall portion 123 a.

The abutment sidewall portion 123 a has an abutment face 123 a 1, onwhich the protuberant rubber portion 35 is adapted to abut and which isformed to be depressed more than the inner face of the thick-walledsidewall portion 123 b toward receding from the outer surface (tip endof the protuberant rubber portion 35) of the main body member 2, asshown in FIG. 2.

By the formation in a depressed manner, the abutment face 123 a 1 of theabutment sidewall portion 123 a can be disposed more distantly from theprotuberant rubber portion 35 of the rubber stopper member 33, andconsequently, it is possible to ensure the amount of stroke toward theroll direction (the direction a or d) without making the car body sidebracket itself large-sized as in the conventional products. Further bythat depressed amount, the thick-walled sidewall portion 123 b is thusformed to be more thick-walled while making the entirety of the car bodyside bracket 120 lightweight, whereby it is possible to ensure thestiffness and strength to enhance the durability of the car body sidebracket 120 as a whole.

Here, a distance between opposed faces (distance in the lateraldirection in FIG. 2) made by the abutment face 123 a 1 of the abutmentsidewall portion 123 a and the outer surface of the main body member 2is made larger (preferably 1.5 times or more, more preferably 2 times ormore) on both acceleration side (the left hand in FIG. 2) anddeceleration side (the right hand in FIG. 2) than a distance betweenopposed faces (distance in the lateral direction in FIG. 2) made by theinner face of the thick-walled sidewall portion 123 b and the outersurface of the main body member 2.

Thereby it is possible to make the projecting height of the protuberantrubber portion 35 larger thereby to make it easy to exhibit its shockabsorbing action. Consequently, upon loading of normal roll motion, theabutment of it against the abutment face 123 a 1 is rendered moderateand it is possible to avoid the generation of booming noise.

On the other hand, upon abrupt acceleration or deceleration oraccidental loading, it is possible to ensure the transitional rubberportion 37 to abut on the thick-walled sidewall portion 123 b therebyregulating an excessive displacement of the hydraulic antivibrationdevice 110. Thereby breakage of the vibration-isolating base 3 can beprecluded. Also in this case, since the thick-walled sidewall portions123 b are made thicker than the abutment sidewall portions 123 a,failure or the like of the sidewall parts 123 can be precluded.

The depressed formation of the abutment face 123 a 1 like this(rendering the abutment sidewall portions 123 a thin-walled) is usuallyunable for the reason that it is the location where the abutment face123 a 1 is subject to input load from the protuberant rubber portion 35.However, this has became possible for the first time by the invention,wherein the car body side bracket 120 is configured in a frame structureconsisting of the bottom face part 122, the sidewall parts 123 and thetop face part 124 and concurrently, the thick-walled sidewall portions123 b thicker than the abutment sidewall portions 123 a are provided andthe abutment sidewall portions 123 a are disposed at locationssurrounded by these thick-walled sidewall portions 123 b and the topface part 124. Thereby weight reduction and securement of strength canbe attained simultaneously.

Both ends (the lateral ends in FIG. 2) of the bottom face part 122 areformed to extend beyond the sidewall parts 123 as illustrated in FIG. 2,and between the upside of the extended end of the bottom face part 122and the outer surface of the sidewall part 123, a reinforcing rib part125 is provided. Thus the stiffness and strength of the car body sidebracket 120 as a whole is ensured.

Now referring to FIG. 3 the construction of the car body side bracket120 will be described in more detail. FIG. 3(a), FIG. 3(b) and FIG. 3(c)are a top plan view, a front elevational view, and a bottom plan view,respectively, of the car body side bracket 120.

As described above, the car body side bracket 120 is provided with thebottom face part 122, the pair of the sidewall parts 123, and the topface part 124, and configured in a frame shape when viewed from thefront side as illustrated in FIG. 3(b). At the upside of the top facepart 124, as illustrated in FIG. 3(a), three reinforcing ribs 124 aextending in the elongated direction (the lateral direction in FIG.3(a)) are provided.

The bottom face part 122 is provided, as illustrated in FIG. 3(c), withthe through-hole for bolt 122 a, the slit portions 122 b, and guidingslope faces 122 c. The bolt through-hole 122 a is a hole for passage ofa bolt (not shown) for locking and fixing the boss member 1 (the boltlocking hole 11) as stated above and configured in a somewhat largerdiameter dimension than the bolt locking hole 11 (cf. FIG. 2).

The slit portions 122 b are slit-like grooves for receiving therein theprotruding pins 12 of the boss member 1 (cf. FIG. 2) as stated above,and provided in two pieces, as shown in FIG. 3(c), so as to extendsubstantially in parallel to each other in positions interposing thebolt through-hole 122 a, having a somewhat larger groove width than theoutside diameter of the protruding pin 12.

Each of the slit portions 122 b is formed at its extended end with theabutment portion 122 b 1 in a semicircular form, and constructed so thatwhen two protruding pins 12 are made to abut on both the abutmentportions 122 b 1, the bolt through-hole 122 a of the bottom face part122 and the bolt locking hole 11 of the boss member 1 may be put intocommunication with each other.

The guiding slope faces 122 c are one pair of slope faces for guidingthe protruding pins 12 of the boss member 1 into the slit portions 122b, and each join with a leading end of the slit portion 122 b, as shownin FIG. 3(c). These paired guiding slope faces 122 c are formed to bewider in distance (lateral distance in FIG. 3(c)) between opposed facesthereof on the peripheral end side of the bottom face part 122 (thelower side in FIG. 3(c)) to enhance the guiding operation.

In this invention, the stiffness and strength upon stopper action isensured by configuring the car body side bracket 120 in a frame shape.However, the configuration of the car body side bracket 120 in a frameshape, on the one hand, causes difficulties in the insertion operationwhen inserting the hydraulic antivibration device 110 within the framework (between the opposed faces of the bottom face part 122 and the topface part 124) of the car body side bracket 120 and in the lockingoperation when locking the bolt into the bolt locking hole 11 of theboss member 1. On the other hand, making the distance between theopposed faces of the bottom face part 122 and the top face part 124wider gives rise to the problem leading to a large-sized constructionand a weight increase of the hydraulic antivibration device arrangement100 as a whole.

On the contrary, according to the invention, the slit portions 122 b areprovided at the bottom face part 122 and constructed so as to receivethe protruding pins 12 therein, and consequently, it is possible toobtain the effect that the aforementioned distance between the opposedfaces can be widened relative to the hydraulic antivibration device 110by that amount.

As a result, it is possible to conduct easily the insertion operation ofinserting the hydraulic antivibration device 110 into the frame of thecar body side bracket 120, to enhance the working efficiency. Further itis possible to construct the aforementioned distance between the opposedfaces narrower, so that downsizing of the hydraulic antivibration devicearrangement 100 as a whole can be achieved.

Further it is readily possible to put the through-hole for bolt 122 a ofthe bottom face part 122 and the bolt locking hole 11 of the boss member1 into communication with each other by moving the protruding pins 12 upto the abutment portions 122 b 1 at the terminal ends of the slitportions 122 b while guiding the protruding pins 12 by the slit portions122 b. Therefore the bolt can be locked easily through the boltthrough-hole 122 a to the bolt locking hole 11, so that it is possibleto elevate the working efficiency of the locking operation.

Again, because the protruding pins 12 and the slit portions 122 b inrespective two pieces are formed and constructed so that the bottom facepart 122 and the boss member 1 are brought into abutment on each otherin two places, reliable positioning of the boss member 1 to the bottomface part 122 can be conducted without relative rotation of the formerto the latter. Therefore, by the abutment of the two protruding pins onthe abutment portions 122 b 1 at two locations, it is possible to putthe bolt through-hole 122 a and the bolt locking hole 11 readily andreliably into communication with each other.

As shown in FIG. 3(c), the two slit portions 122 b are provided toextend straightforwardly toward a substantially orthogonal direction tothe elongated direction (the lateral direction in FIG. 3) of the bottomface part 122 (namely, in a direction inserting the hydraulicantivibration device 110 within the frame of the car body side bracket120), and the lengths of both slit portions 122 b up to the terminalends (namely, respective distances along the vertical direction of FIG.3(c) from the edge ends to the abutment portions 122 b 1 of the bottomface part 122) are made mutually the same.

Therefore, in inserting the hydraulic antivibration device 110 withinthe frame of the car body side bracket 120 and putting the bolt lockinghole 11 of the boss member 1 into communication with the through-holefor bolt 122 a of the bottom face part 122, it will suffice to conductone time operation of inserting the hydraulic antivibration device 110straightforwardly unidirectionally without the necessity of conductingany particular positioning in the rotational direction or lateraldirection, so that its operation efficiency can be enhanced vastly.

Here, at the bottom face part 122 there is formed a tongue-like piece122 d as a residual portion of the slit portions 122 b and the guideslope faces 122 c as shown in FIG. 3(c). The tongue-like piece 122 dperforms the role of a bearing surface (receptive surface) of the bossmember 1. By providing the tongue-like piece 122 d in this manner, it ispossible to ensure its abutment area on the boss member 1, therebyachieving a secure fixing.

As illustrated in FIG. 3(c), the tongue-like piece 122 d has its top endside (the lower side in FIG. 3 c) cut, with its length in the extendeddirection (the vertical direction in FIG. 3(c)) being shortened. Therebywhile pinching the tongue-like piece 122 d between the boss member 1 andthe body frame BF, the tip end of the tongue-like piece 122 d on whichthe boss member 1 does not abut, namely a location of it deviatingbeyond from the peripheral portion of the boss member 1 is suppressedfrom oscillating, whereby it is possible to avoid generation of astrange noise.

Now details of the main body member 2 will be described with referenceto FIGS. 4 through 6. FIG. 4 is a top plan view of the main body member2. FIG. 5(a) is a top plan view of the main body member 2 when viewedfrom the arrow direction Va, while FIG. 5(b) is a side elevation of themain body member 2 when viewed from the arrow direction Vb. FIG. 6(a) isa cross-sectional view of the main body member 2 taken along VIa-VIaline in FIG. 4, and FIG. 6(b) is a cross-sectional view of the main bodymember 2 taken along VIb-VIb line in FIG. 4.

The main body member 2 is, as illustrated in FIGS. 4 or 6, configured ina generally cylinder shape having the central axis O, and on an innerperipheral face thereof, the receptive surface portion 2 b in agenerally triangular shape in cross-section is formed to overhang towardthe central axis direction O. The receptive surface portion 2 b isformed, on its circumferentially one part, with a cutout portion 2 b 1.On the cutout portion 2 b 1, the cutout portion of the lower sandwichingmember 10 is superposed, and the first liquid chamber 6A and the orifice71 are put in communication with each other (cf. FIG. 2).

From the lower end part of the receptive surface portion 2 b (the lowerside in FIG. 6), the main body member 2 is further extended downwardlyas shown in FIG. 6. At the lower end face of the main body member 2,there is disposed the bound side rubber portion 36 of the rubber stoppermember 33 (cf. FIG. 2).

On the upper end face of the main body member 2 as shown in FIGS. 4 or 6(short of the paper face of FIG. 4), the groove 2 c in the form of Ushape in cross-section is defined over the whole circumference. Asdescribed above, the sidewall portion of the groove 2 c on the centralaxis O side is bent to be urged toward the attachment fitting 51,whereby the diaphragm 5 and the partition means 7 are held in the mainbody member 2 (cf. FIG. 2).

As illustrated in FIGS. 4 through 6, the engine side bracket 130 isformed integrally with the outer surface of the main body member 2, fromwhich the projecting main body portion 2 a is provided projectingly. Theengine side bracket 130 is an element linked to the engine EG side (cf.FIG. 1) as stated above, and formed integrally with the outer surface ofthe main body member 2 in its circumferential area of an angle of ca. 90degrees.

The projecting main body portion 2 a is an element encased within theprotuberant rubber portion 35 of the rubber stopper member 33 (cf. FIG.2) as mentioned above, and one pair of the projecting main body portionsare integrally formed with the outer surface of the main body member 2.The pair of the projecting main body portions 2 a are disposed on theouter surface of the main body member 2 (the central axis O) to bespaced apart an angle of ca. 180 degrees from each other.

The pair of the projecting main body portions 2 a are situated, as shownin FIGS. 5 or 6, at a perpendicularly upper end of the main body member2 when viewed from a normal direction to the central axis O. Thereby themain body member 2 is constructed in a manner such that the upper endsurface thereof is flush with the upper end surfaces of the projectingmain body portions 2 a, as illustrated in FIG. 4 or FIG. 6(b).Consequently, even though the groove 2 c for caulking and fixing isprovided on the upper end surface of the main body member 2, the spacefor disposing the rebound side rubber portion 34 can be sufficientlyensured.

Again the pair of the projecting main body portions 2 a are, when viewedfrom the direction of the central axis O, extended in mutually parallelstraight lines. Thereby one pair of the projecting main body portions 2a are, as seen from FIGS. 4 or 5, formed in a transversely elongatedbody extending straight in the width direction of the sidewall parts 123(the vertical direction in FIG. 4, the lateral direction in FIG. 5(b)),while being opposed to the sidewall parts 123 of the car body sidebracket 120 (cf. FIG. 2) at a definite distance from it.

Thereby it is possible simultaneously to ensure a pressure-receivingarea and to ensure a distance spaced apart from the roll center. Thatis, because due to the formation of a transversely elongated shape, itis possible to widen the pressure-receiving area to obtain a dispersioneffect of input load, enhancement of durability and weight reduction canbe achieved. On the other hand, the fact that the projecting main bodyportions 2 a (and the protuberant rubber portion 35) are thus formed inthe transversely elongated body means that the spacing distance from theroll center of the engine EG can be ensured (cf. FIG. 2), andconsequently, as described above, it is possible to make the input loadsto the main body member 2 and the car body side bracket 120 small,thereby simultaneously achieving a weight reduction and a reduction ofbooming noise.

The elongated length (length in the vertical direction in FIG. 4) of theprojecting main body portions 2 a is made approximately the same as thewidth (e.g., the breadth in the vertical direction in FIG. 3(a)) of thesidewall parts 123 of the car body side bracket 120.

Here, the main body member 2 is, as illustrated in FIGS. 5 or 6,provided with the cutout portion 2 d formed by cutting off a part of thelower end side thereof that is situated on the opposite side (the lefthand in FIG. 5(b) and FIG. 6(a)) to the side where the engine sidebracket 130 is formed and on the boss member 1 side. Thereby it ispossible to make the main body member 2 lightweight, thus to achieve aweight reduction by that amount of the hydraulic antivibration devicearrangement 100 as a whole.

The constitution of the invention is such that the main body member 2supports the engine EG in a cantilever fashion, with the boss member 1serving as a fixed point (cf. FIGS. 1 and 2). Here in such constitution,if the top end side (the left hand in FIG. 5(b) or FIG. 6(a)) of themain body member 2 located opposite to the coupling part to the engineEG (the attachment holes 131 side) is heavier, the resonance point ofthe main body member 2 is shifted toward a low frequency range (e.g.,500˜600 Hz and its vicinity), which raised the problem that so-calledhigh-speed booming noise is generated.

On the contrary, the position of the cutout portion 2 d is situated,interposing the boss member 1, on the opposite side to the engine EGcoupling side, namely situated most distantly from the engine EGcoupling side, and hence it is possible to make efficiently the top endside of the main body member 2 lightweight. As a consequence, it ispossible to efficiently shift the resonance point of the main bodymember 2 toward a high frequency range, thereby suppressing securely anadverse effect on dynamic characteristics of the hydraulic antivibrationdevice 110.

Further, this invention is constructed so that the groove 2 c isprovided on the upper end side of the main body member and its sidewallportion is bent up toward the inner periphery side of the main bodymember 2 thereby to caulk and fixe the diaphragm 5 and others. Here,since the position of the cutout portion 2 d is situated on the lowerend side of the main body member 2, it is possible to avoid a reductionin space for forming the groove 2 c by the cutout portion 2 d, as aresult of which the diaphragm 5 and others can be fixed firmly.

The area in which the cutout portion 2 d is formed ranges from theextremity of the main body member 2 (the lower end in FIG. 4, the leftend in FIG. 5(b) or FIG. 6(a)) to a predetermined position, namely islimited to the area where it does not abut on the bottom face part 122of the car body side bracket 120. Therefore even though the bound siderubber portion 36 is constructed on the lower end side of the main bodymember 2 so as to be capable of exhibiting a stopper action of the boundside, it is possible to ensure the area receiving the reaction force toimpingement upon stopper action to achieve a weight reduction, whilesuppressing a reduction in durability of the main body member 2 to theminimum degree.

Again, the main body member 2 is, as shown in FIG. 6(a), provided withthe thin-walled portion 2 e formed by recessing the outer surface of theopposite side (the left hand in FIG. 5(b) and FIG. 6(a)) to the sidethereof where the engine side bracket 130 is provided. Thereby the mainbody member 2 is made lightweight, by which amount it is possible toreduce the weight of the hydraulic antivibration device arrangement 100as a whole. The area in which the thin-walled portion 2 e is formedranges from the top end of the main body member 2 (the lower end in FIG.4, the left end in FIG. 5(b) or FIG. 6(a)) to the positions where theprojecting main body portions 2 a are formed.

Here, the location where the thin-walled portion 2 e is formed issituated, interposing the boss member 1, on the opposite side to theengine EG coupling side, as is the case with the cutout portion 2 dabove, namely situated most distantly from the engine coupling side. Asa consequence, it is possible to reduce the weight of the top end sideof the main body member 2 so efficiently that it is possible to shiftefficiently the resonance point of the main body member 2 to a highfrequency range, thereby suppressing securely an adverse effect on thedynamic characteristics of the hydraulic antivibration device 110.

In this invention, the rubber membrane 31 is formed on the innerperiphery side of the main body member 2, and the partition means 7 andthe diaphragm 5 are inserted while faying with the rubber membrane 31.At that time, since the thin-walled portion 2 e is situated on the outersurface of the main body member 2, by the formation of the thin-walledportion 2 e at a part of the inner periphery of the main body member, itis possible to preclude the thickness of the rubber membrane 31 frombeing uneven in the circumferential direction. As a result, the outerperipheral portions of the partition means 7 and the diaphragm 5 can befayed evenly with the rubber membrane over the full periphery and henceit is possible to prevent the leak of liquid to suppress a reduction indynamic characteristics.

Now with reference to FIGS. 7 and 8, a second embodiment of theinvention will be described. The same parts as those in the firstembodiment are designated by like reference characters, and descriptionof them will be omitted.

FIG. 7 is a cross-sectional view of the hydraulic antivibration devicearrangement 200 in the second embodiment. In the first embodimentdescribed so far, description has been made of the case where the mainbody member 2 of the hydraulic antivibration device 110 is provided withthe projecting main body portions 2 a (cf. FIG. 2), but the hydraulicantivibration device 210 in the second embodiment is, as illustrated inFIG. 7, devoid of the projecting main body portions 2 a. Instead, thesidewall part of the main body member 2 is constructed to be verticallystraight. Thereby it is possible to achieve a weight reduction of themain body member 2.

The omission of such projecting main body portion 2 a is usually unable,inasmuch as the location receives an input load through the protuberantrubber portion 35, but becomes possible for the first time in thisinvention by making the protuberant rubber portion 35 eccentric towardthe upper end side (the upper side in FIG. 7) of the main body member 2thereby reducing an impingement reaction force upon stopper action.Because of that it is possible to achieve simultaneously weightreduction and securement of strength.

Further in the first embodiment described above, the bottom face part122 of the car body side bracket 120 is cut out to form the slitportions 122 b (cf. FIG. 3), whereas in the second embodiment, thebottom face part 122 of the car body side bracket 220 is recessed on itsone face side to form the slit portion 222 b (cf. FIG. 7). Statedanother way, the slit portion 222 is formed as a slot or recessedgroove.

Here, the detailed constructions of the slit portion 222 b and theprotruding pin 212 will be described with reference to FIG. 8. FIG. 8(a)is a perspective view of the boss member 1, and FIG. 8(b) is aperspective view of the bottom face part 122.

One piece of the protruding pin 212 in the second embodiment is providedfrom the boss member 1 as illustrated in FIG. 8(a), and configured in anelongated hole shape having linear lines mutually parallel with bothlateral faces, as viewed in the front elevation.

On the other hand, the slit portion 222 b is, as shown in FIG. 8(b),formed as a recessed groove or slot, which is extended rectilinearlyfrom a marginal edge portion of the bottom face part 122. The width ofthe slit portion 222 b is formed to be the same as or somewhat largerthan the width dimension of the protruding pin 212. The depth of theslit portion 222 b is made shallower than the height of the protrudingpin 212, but the depth may be made deeper than the height.

The slit portion 222 b is formed, at its terminal end in the extendeddirection, with the abutment portion 222 b 1 in a semicircular shape, asillustrated in FIG. 8(b), and constructed so that the bolt through-hole122 a of the bottom face part 122 and the bolt locking hole 11 of theboss member 1 may be put into communication with each other when the endof the protruding pin 212 is brought in abutment on the abutment portion222 b 1.

As a consequence, downsizing of the car body side bracket 220 can beachieved as is the case with the first embodiment above. Simultaneously,since the locking bolt can be locked easily via the bolt through-hole122 a to the bolt locking hole 11 by making the end of the protrudingpin 212 to abut on the abutment portion 122 b 1 while guiding theprotruding pin 212 by the slit portion 222 b, the working efficiency ofsuch locking operation can be enhanced.

Further the protruding pin 212 is configured in an elongated hole shapewhen viewed from the front elevation and the slit portion 222 b isextended rectilinearly, and hence, it is possible to conduct a reliablepositioning of the boss member 1 relative to the bottom face part 122without relative rotation without the necessity of forming respectivetwo pieces of the protruding pins 12 and the slit portions 122 b as inthe first embodiment. Further because the slit portion 222 b is formedas a slot, it is possible to prevent a reduction in strength of thebottom face part 122 as compared with the first embodiment wherein thebottom face part is cut out.

The present invention has been so far described on the basis of thespecific embodiments, but this invention is by no means limited to them,and it will be appreciated that various modifications and variations canbe made within the purview not departing from the spirit or purport ofthe invention.

In the embodiments above, the description has been made of the caseswhere the slit portion 122 b or 222 b is provided on the bottom facepart 122 of the car body side bracket 120 or 220 and the protruding pin12 or 212 is provided on the boss member 1 of the hydraulicantivibration device 110 or 210, but should not always be construed tobe limited to them. For instance, it is naturally possible to providethe bottom face part 122 with the protruding pin while to provide theboss member 1 with the slit portion (slot) receiving the protruding pin.

In the embodiments above, the cases where respective one or two piecesof the slit portion 122 b or 222 b and the protruding pin 12 or 212 areprovided have been described, but the number of them is not limited tothis, and it is naturally possible to provide another pieces of them.For example, three pieces or more is possible.

Again in the first embodiment above, the description has been made ofthe case where the projecting main body portion 2 a is configured in atransversely elongated shape such that extends straight in the widthdirection (the lateral direction in FIG. 5 b) of the sidewall part 123while facing the sidewall part 123 of the car body side bracket 120 at adefinite distance.

Here, it is preferred that the transversal width dimension (the lateraldirection dimension in FIG. 5 b) of the projecting main body portion 2 abe equal to the width dimension (the perpendicular dimension to thepaper face in FIG. 3 b) of the sidewall part 123 of the car body sidebracket 120. This is because if the transversal width dimension issmall, the pressure receiving area to the reaction force to impingementcannot be ensured, resulting in a reduction in durability, whereas ifthe transversal width dimension is large, a weight increase is resulted.

1. A hydraulic antivibration device arrangement comprising: a hydraulicantivibration device which comprises a cylindrical main body member, aboss member situated on a lower end face side of the main body member, avibration-isolating base made of rubber-like elastomer materialconnecting the boss member and the main body member, a diaphragmattached to the main body member to define a liquid-filled chamberbetween the diaphragm and the vibration-isolating base, partition meanscomparting the liquid-filled chamber into a first liquid chamber on thevibration-isolating base side and a second liquid chamber on thediaphragm side, an orifice putting the first liquid chamber and thesecond liquid chamber into communication with each other, and a rubberstopper member made of rubber-like elastomer material provided on anouter surface of the main body member; an engine side bracket formedintegrally with the main body member of the hydraulic antivibrationdevice and to be coupled to the engine side; and a car body side bracketwhich includes a bottom face part to which the boss member of thehydraulic antivibration device is locked and fixed, a pair of sidewallparts provided perpendicularly from the bottom face part and opposed toeach other, interposing the hydraulic antivibration device therebetween,and a top face part interconnecting the pair of the sidewall parts andopposed to the bottom face part, interposing the hydraulic antivibrationdevice between the bottom face part and the top face part, and isadapted to be connected to a car body frame side; and constructed tosupport the engine in a suspending manner and to be capable of bringingthe rubber stopper member provided on the outer surface of the main bodymember into abutment on internal faces of the sidewall parts of the carbody side bracket, thereby regulating displacement of the engine in aroll motion direction at least upon acceleration, which arrangement ischaracterized in that the rubber stopper member is provided with aprotuberant rubber portion protruding from the outer surface of the mainbody member toward the sidewall parts of the car body side bracket andtapering in cross-section, and the protuberant rubber portion issituated at least on an upper end side above a vertically intermediateposition of the main body member and configured in a transverselyelongated body extending straight widthwise toward the sidewall parts ofthe car body side bracket while facing the sidewall parts in a spacedrelation of a definite distance; and that the sidewall parts of the carbody side bracket each include an abutment sidewall portion having anabutment face on which the protuberant rubber portion of the rubberstopper member abuts and a thick-walled sidewall portion formed to bemore thick-walled than the abutment sidewall portion, and the abutmentface of the abutment sidewall portion is formed to be depressed from theinner face of the thick-walled sidewall portion toward receding from theouter surface of the main body member.
 2. The hydraulic antivibrationdevice arrangement as claimed in claim 1, characterized in that the mainbody member is provided with a projecting main body portion projectingfrom the outer surface of the main body member toward the sidewall partsof the car body side bracket, and the projecting main body portion issituated on the upper end side above the vertically intermediateposition of the main body member and configured in the transverselyelongated body extending straight widthwise toward the sidewall parts,while facing the sidewall parts of the car body side bracket at adefinite distance and encased in the protuberant rubber portion of therubber stopper member.
 3. The hydraulic antivibration device arrangementas claimed in claim 1 or 2, characterized in that the main body memberis provided with a cutout portion defined by cutting a part of anunderside thereof situated on the opposite side to the engine sidebracket and on the boss member side.
 4. The hydraulic antivibrationdevice arrangement as claimed in claim 1 or 2, characterized in that themain body member is provided with a thin-walled portion formed bydepressing the outer surface thereof opposite to the engine sidebracket.
 5. The hydraulic antivibration device arrangement as claimed inclaim 1 or 2, characterized in that the arrangement further comprises: aprotruding pin provided to project from one of the bottom face part ofthe car body side bracket and the boss member and a slit portion servingas a guide path for the protruding pin and provided to extend at theother of the bottom face part of the car body side bracket and the bossmember, and the slit portion has an abutment portion provided at itsextended extremity; and that the bottom face part of the car body sidebracket has a through-hole for a bolt and the boss member has a lockinghole for the bolt so that when the protruding pin is made to abut on theabutment portion of the slit portion, the through-hole and the lockinghole for the bolt may be put in communication with each other.
 6. Thehydraulic antivibration device arrangement as claimed in claim 5,characterized in that two pieces of the protruding pins are providedprojectingly at one of the bottom face part of the car body side bracketand the boss member, and two pieces of the slit portions are provided toextend at the other of the bottom face part of the car body side bracketand the boss member; and that the two protruding pins and the two slitportions are constructed so that when the two protruding pins are madeto abut on the abutment portions of the two slit portions respectively,the through-hole and the locking hole for the bolt may be put intocommunication with each other.
 7. The hydraulic antivibration devicearrangement as claimed in claim 1 or 2, characterized in that the rubberstopper member includes a rebound side rubber portion and a bound siderubber portion provided respectively on an upper end surface and a lowerend surface of the main body member; and the rebound side rubber portionand the bound side rubber portion are constructed so as to be capable ofregulating the displacement in a rebound direction and a bound directionof the hydraulic antivibration device by abutment of them on the topface part and the bottom face part of the car body side bracket,respectively.
 8. The hydraulic antivibration device arrangement asclaimed in claim 7, characterized in that the projecting main bodyportion of the main body member projecting from the outer surfacethereof is situated on an uppermost end side of the main body member andconstructed so that upper end surfaces of the projecting main bodyportion and the main body member are flush with each other.
 9. Ahydraulic antivibration device characterized by being used for thehydraulic antivibration device arrangement as claimed in claim 1 or 2.10. A car body side bracket characterized by being used for thehydraulic antivibration device arrangement as claimed in claim 1 or 2.